Data Collections and Follow-Up In the randomized controlled trial (Aim 1 and 2), data will be collected at inclusion, after the 15 weeks intervention period, and at follow- ups at 6 months, 1 year, and 2 years. Data from all outcome measurements will be collected from all patients at all follow-ups, except for the gait-analysis data (kinematic and kinetic data) (Aim 2). These data will be collected at inclusion and after the intervention period (15 weeks).